Find the local maximum and minimum values of the following curve within the given domain.

Question

y=SECx-TANx 0 ≤ x ≤ 2π

Answer 1

y = secx - tanx
y' = secx(tanx-secx)

y' = 0 when
secx=0 -- never

tanx-secx=0
secx(sinx-1) = 0
secx=0 -- never
sinx=1 -- x = pi/2

Now, we want x=pi/2 to be a solution, but unfortunately, neither secx nor tanx is defined there.

There are no min/max points on the graph of f(x), as seen at this url:

http://www.wolframalpha.com/input/?i=secx+-+tanx